Alfred heezheim



bear.

NrTED STATES PATENT 'OFFICE.

ALFRED HERZHEIM, OF BERLIN, GERMANY, ASSIGNOR TO THE OI'IEMISCHE FABRIK AUF AOTIEN, VORMALS E. SOHERING, OE SAME PLACE.

WATERPROOF PAPER.

SPECIFICATION formingpart of Letters Patent No. 602,558, dated April 19, 1898.

Application filed June 7,1897. Serial No. 639,729. (No specimens.) Patented in Germany July 27, 1895,1I0. 86,938; in England November 26,1895, No. 22,625; in France December 16, 1895, No. 252,501; in Belgium December 16, 1895, No. 118,877; in Hungary June 22, 1896, No. 6,310, and in Austria July 10, 1896,110. LB/2,756.

T aZZ whom it may concern.-

Be it known that I, ALFRED HERZHEIM, a subject of the German Emperor, residing in the city of Berlin, Germany, have invented new and useful Improvements in lVaterproof Paper, (for which I have obtained a patent in Germany, No. 86,938, dated July 27, 1895; in

England, No.22,625,datedNovember26, 1895; in France, No. 252,501, dated December 16,

[O 1895; in Belgium, No. 118,877, dated December 16, 1895; in Hungary, No. 6,310, dated June 22, 1896, and in Austria, No. 46/2756, dated July 10, 1896,) of which the following is a specification.

This invention relates to the manufacture of water and grease proof paper in a simple and effective manner and without the employment of ingredients which are in any way 0bject-iouable with reference to the use of the paper.

In practicing this invention sulfite cellulose is ground or reduced with water in a ragengine or pulping-machinehaving dull knives until the cellulose is reduced to a transparent or translucent gelatinous condition, usually from ten to fifteen hours. This mechanical treatment changes the sulfite cellulose to a substance which closely resembles hydrocellulose in its properties. This modified sulfite-cellulose pulp is manufactured into paper in any common and well-known way. This paper is drawn through or immersed in or otherwise coated with a solution of pyroxy- .lin in any suitable solventfor instance, in

3 5 acetic ether, a mixture of ether and alcohol,

methyl-alcohol, or acetone and alcohol. The solvent of the pyroxylin loosens or softens the surface portions of this kind of paper sufficiently to cause a close and permanent union of the pyroxylin with the paper after 40 the evaporation of the solvent, which union is not destroyed by hot or cold water, Weak acids, &c. The evaporated solvent can be recovered by condensation and be again used.

The pyroxylin enters the loosened or softened surface portion of the paper and unites with it so intimately that it becomes permanently united with the paper. The paper prepared in this manner effectually resists the action of warm as well as cold water, grease, oil, and weak acids, and is not easily permeated by air. The paper contains no ingredients which are in any way objectionable in any use to which the paper can be putfor instance, in photography, for packing butter, margarin grease, su bstances containing acids, munitions of war, &c.

I claim as my invention The herein-described waterproof paper consisting of a body which is composed of the herein-described modified sulfite cellulose resembling hydrocellulose and a coating of pyroxylin permanently united therewith, substantially as set forth.

Witness my hand this 11th day of March, 1897.

. ALFRED HERZHEIM.

Witnesses:

HENRY HASPER, W. HAUPT. 

